CaltechAUTHORS: Combined
https://feeds.library.caltech.edu/people/Watson-R/combined.rss
A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenFri, 21 Jun 2024 19:58:43 -0700Effect of scale size on a rocket engine with suddenly frozen nozzle flow
https://resolver.caltech.edu/CaltechAUTHORS:20110111-082616427
Year: 1961
Recent analytical work by Bray indicates that single
element, chemically reacting systems, e.g., H_2 ⇋ 2H, may
suddenly freeze their composition at some point in a high
speed nozzle and then remain at fixed composition
throughout the remainder of the expansion. This sudden
freezing or "quenching" phenomenon was also apparent
in some theoretical calculations reported by Hall et al.
and has been verified experimentally by Wegener. It
is the purpose of this note to show qualitatively how
Bray's sudden-freezing criterion is related to engine size
by the scale factor for geometrically similar engines having
n on equilibrium nozzle flows and in which a propellant
system is used for which Bray's analysis is valid.https://resolver.caltech.edu/CaltechAUTHORS:20110111-082616427Reduction of ultraviolet scattering from a continuous light source in a littrow type monochromator
https://resolver.caltech.edu/CaltechAUTHORS:20110106-135634209
Year: 1962
DOI: 10.1366/000370262774416164
Quantitative spectroscopic experiments in shock tubes such as f-number measurements [for example (1)] require an absolute calibration of the optical system, monochromator, and detector. This is very often done for ultraviolet transitions around 3000-3500A with a tungsten strip filament lamp for which emissivities are known (2).https://resolver.caltech.edu/CaltechAUTHORS:20110106-135634209Temperature measurement on the OH ^2Σ→^2Π band system for a transparent gas in a shock tube
https://resolver.caltech.edu/CaltechAUTHORS:20110106-131913150
Year: 1962
DOI: 10.1016/0022-4073(62)90006-7
N/Ahttps://resolver.caltech.edu/CaltechAUTHORS:20110106-131913150Procedure for reliable preparation of shock tube test gas mixtures containing water vapor
https://resolver.caltech.edu/CaltechAUTHORS:20110106-152408147
Year: 1962
DOI: 10.1063/1.1717700
N/Ahttps://resolver.caltech.edu/CaltechAUTHORS:20110106-152408147Experimental spectroscopic temperature measurement in the reflected wave region of a shock tube using the OH^2∑ → ^2Π band system
https://resolver.caltech.edu/CaltechAUTHORS:20110104-104430745
Year: 1963
DOI: 10.1016/0022-4073(63)90036-0
Experimental measurements of the population temperature behind the reflected shock in a shock tube are presented. Emission from two wave length intervals of the OH^2∑ → ^2Π electronic band system was measured photoelectrically, the signals observed being generated by a narrow core of hot
gas in the reflected shock region looking axially up the tube. The ratio of the rate of increase of intensity,
per unit increase of optical depth, in the two spectral regions is a unique function of the temperature for
a transparent gas. The linearity of the signal increase with time represents an experimental verification
of the transparency and equilibrium of the test gas.
In the temperature range of 3300-4300°K (M_s ~ 4), the measured spectroscopic temperature was in good agreement with the calculated equilibrium temperature, the estimated accuracy of the spectroscopic temperature being ± 75°K. A relaxation time of about 25 µsec was observed for the (2,2) and (3,3) vibration bands to reach statistical equilibrium with the lower (0,0) and (1,1) vibrational levels in the ^2∑
state from which the emission occurred.https://resolver.caltech.edu/CaltechAUTHORS:20110104-104430745A Joint Analysis of BICEP2/Keck Array and Planck Data
https://resolver.caltech.edu/CaltechAUTHORS:20150205-194356590
Year: 2015
DOI: 10.1103/PhysRevLett.114.101301
We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg2 patch of sky centered on RA 0 h, Dec. −57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r0.05<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.https://resolver.caltech.edu/CaltechAUTHORS:20150205-194356590